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1.
Ecol Lett ; 22(7): 1136-1144, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31074933

RESUMEN

Sodium is unique among abundant elemental nutrients, because most plant species do not require it for growth or development, whereas animals physiologically require sodium. Foliar sodium influences consumption rates by animals and can structure herbivores across landscapes. We quantified foliar sodium in 201 locally abundant, herbaceous species representing 32 families and, at 26 sites on four continents, experimentally manipulated vertebrate herbivores and elemental nutrients to determine their effect on foliar sodium. Foliar sodium varied taxonomically and geographically, spanning five orders of magnitude. Site-level foliar sodium increased most strongly with site aridity and soil sodium; nutrient addition weakened the relationship between aridity and mean foliar sodium. Within sites, high sodium plants declined in abundance with fertilisation, whereas low sodium plants increased. Herbivory provided an explanation: herbivores selectively reduced high nutrient, high sodium plants. Thus, interactions among climate, nutrients and the resulting nutritional value for herbivores determine foliar sodium biogeography in herbaceous-dominated systems.


Asunto(s)
Pradera , Herbivoria , Sodio , Adaptación Fisiológica , Animales , Nitrógeno , Plantas , Suelo
2.
J Phys Chem A ; 123(46): 10057-10064, 2019 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-31670512

RESUMEN

Superfluid helium nanodroplets comprised of thousands to millions of helium atoms can serve as a reactor for the synthesis of heterogeneous molecular clusters at cryogenic conditions. The cluster synthesis occurs via consecutive pick-up of the cluster building blocks by the helium droplet and their subsequent coalescence within the droplet. The effective collision cross section of the building blocks is determined by the helium droplet size and thus exceeds by orders of magnitude that of a reactive collision in the gas phase. Moreover, the cryogenic helium environment (at 0.38 K) as a host promotes the formation of metastable cluster configurations. The question arises as to the extent of the actual involvement of the helium environment in the cluster formation. The present study deals with clusters of single phthalocyanine (Pc) molecules with single water molecules. A large fluorophore such as Pc offers several sites where the water molecule can attach. The resulting isomeric variants of the Pc-H2O complex can be selectively identified by electronic spectroscopy. We compare the experimental electronic spectra of the Pc-H2O complex generated in superfluid helium nanodroplets with the results of quantum-chemical calculations on the same cluster but under gas-phase conditions. The number of isomeric variants observed in the helium droplet experiment comes out the same as that obtained from our gas-phase calculations.

3.
Anaesthesist ; 68(9): 615-617, 2019 09.
Artículo en Alemán | MEDLINE | ID: mdl-31463544

RESUMEN

Sonographically controlled blockade of the distal sciatic nerve is usually performed by placing the ultrasound probe on the dorsal side of the thigh. This requires positioning maneuvers (prone or side positioning) of the patient as well as additional assistance. In order to avoid these positioning maneuvers, a positioning aid with integrated ultrasound probe holder has been developed and its practicability was examined on patients with lower limb surgery. The sonographically controlled block of the sciatic nerve was performed with the patient under general anesthesia and in a supine position with the help of the new positioning aid with an integrated ultrasound probe holder. A total of >100 patients were treated, who underwent elective lower leg, ankle or foot surgery with a continuous blockade of the distal sciatic nerve using catheters for postoperative analgesia. The advantages are easy performance, hands-free needle movement and catheter placement. The disadvantages might be the need for in-plane catheter placement and a fixed ultrasound angle.


Asunto(s)
Bloqueo Nervioso/instrumentación , Bloqueo Nervioso/métodos , Nervio Ciático/efectos de los fármacos , Ultrasonografía Intervencional/instrumentación , Ultrasonografía Intervencional/métodos , Anestesia General , Humanos , Nervio Ciático/diagnóstico por imagen
4.
Orthopade ; 47(3): 238-245, 2018 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-29327070

RESUMEN

BACKGROUND: Operative refixation is a new therapeutic option in cases of failed conservative treatment for trochanteric pain syndrome (TPS) and lesions of the hip abductors in magnetic resonance imaging (MRI). OBJECTIVE: Evaluation of the clinical and radiological results after open gluteus medius and minimus tendon reconstruction with a double-row technique was carried out. MATERIAL AND METHODS: Patients with failed conservative treatment for TPS and confirmed lesions of the hip abductors in MRI were treated by open hip abductor tendon reconstruction with a double-row technique. The patients were evaluated preoperatively and postoperatively (minimum follow-up 12 months) using the modified Harris hip score (mHHS) and a subjective score (subjective hip value, SHV). Preoperative and postoperative MRI evaluation included measurement of hip abductor muscle diameter and cross-sectional area as well as fatty degeneration. RESULTS: In this study 12 consecutive cases of open reconstruction of the hip abductor tendons were included. There was a significant improvement in the mHHS. In one case the patient showed an atraumatic rupture in the proximal anchor row. The MRI showed a significant improvement in muscle diameter and cross-sectional area for the gluteus medius muscle of the affected and the contralateral side, while the degree of fatty degeneration did not improve. The fatty degeneration showed a significant correlation with the postoperative results in the mHHS and the SHV. CONCLUSION: Operative reconstruction of lesions in the hip abductor tendons is a therapy option with significant improvement of patient satisfaction and functional scores as well as muscle diameter and cross-sectional area for the gluteus medius. The degree of fatty degeneration and possible differential diagnoses need to be taken into consideration.


Asunto(s)
Nalgas/lesiones , Músculo Esquelético/lesiones , Complicaciones Posoperatorias/diagnóstico por imagen , Traumatismos de los Tendones/cirugía , Adulto , Anciano , Nalgas/diagnóstico por imagen , Nalgas/cirugía , Estudios de Seguimiento , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Músculo Esquelético/diagnóstico por imagen , Músculo Esquelético/cirugía , Estudios Retrospectivos , Traumatismos de los Tendones/diagnóstico por imagen
5.
Unfallchirurg ; 120(2): 103-109, 2017 Feb.
Artículo en Alemán | MEDLINE | ID: mdl-28054122

RESUMEN

BACKGROUND: An implant used for stabilizing a fracture creates a mechanical construct, which directly determines the biology of bone healing. The stabilization of fractures places high mechanical demands on implants and therefore steel and titanium are currently almost exclusively used as the materials of choice. OBJECTIVES: The possible range of attainable mechanobiological stimulation for mechanotherapy as a function of plate stiffness depending on the selection of the plate material and the physical and mechanical properties of the material options are discussed. MATERIAL AND METHODS: An overview of the material properties of steel and titanium is given. For dynamically fixed long bone fractures as examples, various finite element models of plate osteosynthesis (steel/titanium) are created and the plate working length (PWL, screw configuration close to fracture) is varied. The interfragmentary movement (IFM) as a measure of mechanobiological stimulation is evaluated. RESULTS: Stimulation in the form of IFM varies across the fracture and also as a function of the osteosynthesis material and the configuration. The influence of the material appears to be notably smaller than the influence of PWL but both lose their influence largely over a bridged fracture situation (contact). With a flexible titanium plate and large PSS, a greater mechanobiological stimulation is produced. CONCLUSION: An essential prerequisite for the secondary fracture healing is an appropriate mechanobiological environment, which can be controlled by the osteosynthesis material and the configuration and is also affected by the type of fracture and load.


Asunto(s)
Curación de Fractura/fisiología , Fracturas Óseas/fisiopatología , Fracturas Óseas/terapia , Modelos Biológicos , Acero/química , Titanio/química , Animales , Simulación por Computador , Módulo de Elasticidad , Humanos , Ensayo de Materiales , Diseño de Prótesis , Estrés Mecánico
6.
Unfallchirurg ; 120(6): 454-460, 2017 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-28540566

RESUMEN

Osteosynthesis-associated infections occur in 1-5% after closed and in up to 30% after open fractures. There are three different descriptions of implant-associated infections after fracture fixation, which are crucial for the selection of the adequate treatment strategy; temporal appearance from the index surgery (early versus late), pathogenesis of the infection (exogenous, hematogenous and contiguous from an adjacent focus), duration of infection symptoms (acute versus chronic). Diagnosis of osteosynthesis-associated infection is challenging, as chronic low-grade infections often present only with unspecific and subtle clinical symptoms. History, clinical evaluation, imaging, histopathlogical and microbiological examination build the cornerstones of diagnostics in implant-associated infections. A new onset of rest pain, early loosening of the prosthesis or mechanically unexplained, nonunion should raise suspicion for infection and prompt further evaluation. Percutaneous sinus tracts, purulent wound secretion and skin erosions with visibility of the implant confirm the implant-associated infection. Elevated C­reactive protein value in blood is a supportive argument for infection, but is neither sensitive nor specific for infection. Imaging plays a key role to detect nonunions, infectious callus, sequester, peri-implant osteolysis and extraosseous and intramedullary involvement. Through microbiological and histopathological examination of intraoperative tissue samples, as well as sonication of explanted implants the causative pathogen is identified in most cases.


Asunto(s)
Técnicas de Laboratorio Clínico/estadística & datos numéricos , Fijación Interna de Fracturas/estadística & datos numéricos , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/epidemiología , Infecciones Relacionadas con Prótesis/diagnóstico , Infecciones Relacionadas con Prótesis/epidemiología , Terminología como Asunto , Causalidad , Técnicas de Laboratorio Clínico/métodos , Diagnóstico Diferencial , Medicina Basada en la Evidencia , Alemania/epidemiología , Humanos , Complicaciones Posoperatorias/clasificación , Prevalencia , Infecciones Relacionadas con Prótesis/clasificación , Factores de Riesgo
7.
Eur Cell Mater ; 32: 87-110, 2016 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-27434267

RESUMEN

Despite the high innate regenerative capacity of bone, large osseous defects fail to heal and remain a clinical challenge. Healing such defects requires the formation of large amounts of bone in an environment often rendered hostile to osteogenesis by damage to the surrounding soft tissues and vasculature. In recent years, there have been intensive research efforts directed towards tissue engineering and regenerative approaches designed to overcome this multifaceted challenge. In this paper, we describe and critically evaluate the state-of-the-art approaches to address the various components of this intricate problem. The discussion includes (i) the properties of synthetic and natural scaffolds, their use in conjunction with cell and growth factor delivery, (ii) their vascularisation, (iii) the potential of gene therapies and (iv) the role of the mechanical environment. In particular, we present a critical analysis of where the field stands, and how it can move forward in a coordinated fashion.


Asunto(s)
Regeneración Ósea/fisiología , Huesos/patología , Ingeniería de Tejidos/métodos , Animales , Sistemas de Liberación de Medicamentos , Terapia Genética , Humanos , Andamios del Tejido/química
8.
Pathologe ; 37(4): 367-70, 2016 Jul.
Artículo en Alemán | MEDLINE | ID: mdl-27271257

RESUMEN

Primary sarcomas and sarcoma metastases are a rarity in the spleen. We report on the case of a 69-year-old male patient presenting with unclear abdominal symptoms and computed tomography (CT) revealed a tumor mass in the spleen. Histologically the tumor mass predominantly showed features of a spindle cell sarcoma with lymphoid infiltrates. The expression and amplification of MDM2 could be demonstrated by means of immunohistochemistry and fluorescence in situ hybridization (FISH). Furthermore, staging examinations did not reveal indications of any other primary tumors. These preliminary findings were suggestive of a dedifferentiated liposarcoma; however, in the further diagnostic work-up the tumor showed strong expression of CD21 and CD23 and was ultimately diagnosed as a follicular dendritic cell sarcoma (FDCS). The case emphasizes that MDM2 expression represents a possible pitfall in the diagnosis of spindle cell tumors. The differential diagnostic distinction between FDCS and a dedifferentiated liposarcoma is discussed.


Asunto(s)
Liposarcoma/genética , Liposarcoma/patología , Proteínas Proto-Oncogénicas c-mdm2/genética , Sarcoma/genética , Sarcoma/patología , Neoplasias del Bazo/genética , Neoplasias del Bazo/patología , Anciano , Diagnóstico Diferencial , Humanos , Liposarcoma/cirugía , Masculino , Sarcoma/cirugía , Bazo/patología , Esplenectomía , Neoplasias del Bazo/cirugía , Tomografía Computarizada por Rayos X
9.
J Dairy Sci ; 97(7): 4568-78, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24792796

RESUMEN

Pasture-based dairy producers in the United States face costs, revenue streams, and management challenges that may differ from those associated with confinement dairy production systems. Three Grazing Merit indices (GM$1, GM$2, and GM$3), parallel to the US Lifetime Net Merit (NM$) index, were constructed using economic values appropriate for grazing production in the United States. Milk prices based on averages from the previous 5 yr were used for GM$1, whereas GM$2 and GM$3 used milk prices found in NM$. Cull prices and interest rates from NM$ were used in GM$3 but were updated for GM$1 and GM$2. All other inputs remained constant among GM$1, GM$2, and GM$3. Economic costs and revenues were obtained from surveys, recent literature, and farm financial record summaries. Derived weights for GM$ were then multiplied by the predicted transmitting abilities of 584 active artificial insemination Holstein bulls to compare with NM$. Spearman rank correlations for NM$ were 0.93 with GM$1, 0.98 with GM$2, and 0.98 with GM$3. Traits (and their percentages of weight) comprising GM$1, GM$2, and GM$3, respectively, included milk volume (24, 0, 0%), Fat yield (16, 21, 21%), protein yield (4, 17, 17%), productive life (7, 8, 7%), somatic cell count (-8, -9, -9%), feet and legs composite (4, 4, 4%), body size composite (-3, -4, -4%), udder composite (7, 8, 8%), daughter pregnancy rate (18, 20, 20%), calving ability (3, 3, 3%), and dairy form (6, 6, 6%). These weights compared with NM$ weights of 0, 19, 16, 22, 10, 4, 6, 7, 11, 5, and 0% for the same traits, respectively. Dairy form was added to GM$ to offset the decrease in strength associated with selection to reduce stature through selection against body size. Emphasis on productive life decreased in GM$ because grazing cattle are estimated to remain in the herd considerably longer, diminishing the marginal value of productive life. Although NM$ provides guidance for grazing dairy producers, a GM$ index based upon appropriate costs and revenues allows for selection of cows and bulls for more optimal genetic progress.


Asunto(s)
Cruzamiento , Bovinos/fisiología , Industria Lechera/métodos , Animales , Bovinos/genética , Industria Lechera/economía , Femenino , Masculino , Modelos Económicos , Embarazo , Estados Unidos
10.
Pathologe ; 35(2): 191-5, 2014 Mar.
Artículo en Alemán | MEDLINE | ID: mdl-23793289

RESUMEN

Primary Hodgkin's lymphoma of the colon is exceedingly rare. We report on the case of a 74-year-old female patient presenting with weight loss and hematochezia. Proctocolonoscopy revealed a bleeding tumor localized in the right colonic flexure. Histological examination of initial mucosal biopsies could not verify malignancy; however, explorative surgery was decided in an interdisciplinary conference setting and right-sided hemicolectomy was performed. Macroscopically, a tumor measuring 5.5 cm in maximum diameter was found. By means of histology and immunohistochemistry the diagnosis of classic Hodgkin's lymphoma was made. Mesenteric lymph nodes were not affected and postoperative staging revealed no systemic spread. Therefore, the tumor fulfilled the criteria of a primary colonic Hodgkin's lymphoma. Diagnosis of primary colonic lymphoma can be difficult as clinical symptoms are typically unspecific and, as shown in this case, even primary biopsy histology can be falsely negative.


Asunto(s)
Neoplasias del Colon/patología , Enfermedad de Hodgkin/diagnóstico , Enfermedad de Hodgkin/patología , Anciano , Biopsia , Colectomía , Neoplasias del Colon/diagnóstico , Neoplasias del Colon/cirugía , Colonoscopía , Reacciones Falso Negativas , Femenino , Enfermedad de Hodgkin/cirugía , Humanos , Mucosa Intestinal/patología , Ganglios Linfáticos/patología , Estadificación de Neoplasias
11.
Anaesthesist ; 63(6): 488-95, 2014 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-24820355

RESUMEN

BACKGROUND: Delirium is defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition, text revision (DSM-IV-TR) as a potentially reversible disturbance of consciousness and a change of cognition caused by a medical condition, drug intoxication, or medication side effect. Delirium affects up to 80 % of intensive care unit (ICU) patients and is associated with increased morbidity and mortality. One risk factor for development of delirium in ventilated intensive care unit patients is sedation. The German S3 guidelines on "Analgesie, Sedierung und Delirmanagement in der Intensivmedizin" (analgesia, sedation and delirium management in intensive care medicine) of the DGAI (German Society for Anesthesiology and Intensive Care Medicine) and the DIVI (German Interdisciplinary Association for Intensive Care and Emergency Medicine) recommend midazolam and propofol for sedation, although both drugs are associated with a high incidence of delirium. AIM: Within the framework of this study the question arose whether the barbiturate methohexital could be associated with a lower incidence of delirium in comparison to midazolam or propofol in analgosedated and ventilated ICU patients. MATERIAL AND METHODS: This was a prospective nonrandomized observational cohort study in a mixed medical surgical intensive care unit. Patients ventilated within 72 h after admittance were consecutively allocated to either propofol/remifentanil versus methohexital/remifentanil (expected ventilation duration ≤ 7 days) or midazolam/fentanyl versus methohexital/fentanyl (expected ventilation duration > 7 days) by the attending senior consultant anesthetist at the time of admission and/or intubation. Primary endpoint was delirium at any time during the ICU stay. Delirium was checked every 8 h by ICU nurses using the intensive care delirium screening checklist (ICDSC), with delirium defined as ICDSC ≥ 4 points. Before evaluation of the ICDSC the Richmond agitation sedation scale (RASS) score and the visual analogue scale for pain (VAS target ≤ 4) were measured. To assure reliable evaluation of the ICDSC, the RASS score of the patient at the time of evaluation had to be ≥ - 2. Assuming an incidence of delirium in the midazolam group of 70 % and in the methohexital group of 35 %, 16 patients were needed each in the midazolam/fentanyl and the methohexital/fentanyl cohorts (p = 0.05, ß = 0.1). Assuming an incidence of delirium in the propofol group of 50 % and in the methohexital group again of 35 %, 94 patients were needed in the propofol/remifentanil and methohexital/remifentanil groups, respectively (p = 0.05, ß = 0.1). RESULTS: A total of 222 patients were evaluated, 34 in the methohexital vs. midazolam group and 188 in the methohexital vs. propofol group. Out of 16 patients sedated with midazolam, 15 developed delirium (94 %) in contrast to only 5 out of 18 patients sedated with methohexital (28 %). Thus compared to midazolam the sedation with methohexital reduced the incidence of delirium by 66 % (p < 0.001) corresponding to a number needed to treat (NNT) of 1.5. Out of 94 patients in the propofol/remifentanil group, 64 developed delirium (68 %) in contrast to only 23 out of 94 in the methohexital/remifentanil group (24 %). Thus compared to propofol the sedation with methohexital reduced the incidence of delirium by 44 % (p < 0.001), corresponding to an NNT of 2.5. CONCLUSION: Sedation with methohexital compared to midazolam or propofol reduced the incidence of delirium by more than 50 % in ventilated ICU patients.


Asunto(s)
Anestésicos Intravenosos/uso terapéutico , Delirio/epidemiología , Delirio/prevención & control , Hipnóticos y Sedantes/uso terapéutico , Metohexital/uso terapéutico , Respiración Artificial/métodos , Anciano , Analgésicos Opioides/uso terapéutico , Lista de Verificación , Estudios de Cohortes , Cuidados Críticos , Quimioterapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Piperidinas/uso terapéutico , Propofol/uso terapéutico , Estudios Prospectivos , Agitación Psicomotora/prevención & control , Remifentanilo
12.
J Dairy Sci ; 96(6): 3639-51, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23587383

RESUMEN

Some housing systems on dairy farms can result in long-term chronic pain. The effects of acute pain on immunity have been explored, but chronic pain's influence on immune responses is still poorly understood. Therefore, the objective of this research was to determine chronic effects of flooring on immune responses and production in freestall housing for dairy cows. Thirty heifers were studied from before calving as first-calf heifers until d 180 of their second lactation. Treatments were rubber (Kraiburg; Agromatic Inc., Fond du Lac, WI) flooring or concrete with diamond grooves in a freestall barn, each in 2 quadrants of the barn. Heifers entered the treatments after calving, so the system was dynamic and each cow was considered an experimental unit. At the end of the first lactation, cows were housed in a bedded pack barn with pasture access until calving was imminent. At that time, they returned to their assigned treatment, but not necessarily into the same quadrant. Production, reproduction, cortisol, acute-phase proteins, and health data were recorded throughout lactation 1, locomotion was scored weekly, and hoof scoring and care was conducted on d 60 and 180 of lactations 1 and 2, and quantitative real-time-PCR of blood leukocytes was analyzed in mid lactation of lactation 1. Mature-equivalent milk fat, milk protein, and protein percentages during the first lactation were greater for cows on the rubber flooring. Hoof and leg therapy treatments per cow were fewer for rubber floor-housed cows. Locomotion scores were less for cows housed on rubber during the second lactation. White blood cell counts were less for cows housed on rubber, and caused by greater lymphocyte counts for cows housed on concrete. The possibility of chronic inflammation was substantiated by less IL-1ß and more IL-1 receptor antagonists for cows housed on rubber at d 150 in the second lactation. Cortisol and acute-phase proteins did not differ between the treatments. Interferon-γ, IL-12, the modulator of tissue reconstruction (B-cell-transforming growth factor 1), and pain-modulating neurokinin (tachykinin 1) were not different at d 105. These data show indicators of chronic inflammation for cows housed on the concrete flooring compared with those housed on rubber. Implications for the use of rubber flooring in freestall barns are broader than just lameness and may affect many aspects of cow physiology and production.


Asunto(s)
Enfermedades de los Bovinos/prevención & control , Pisos y Cubiertas de Piso , Vivienda para Animales , Lactancia/fisiología , Cojera Animal/prevención & control , Goma , Proteínas de Fase Aguda/análisis , Animales , Bovinos/inmunología , Bovinos/fisiología , Enfermedades de los Bovinos/inmunología , Enfermedades de los Bovinos/fisiopatología , Grasas/análisis , Femenino , Pisos y Cubiertas de Piso/instrumentación , Pezuñas y Garras , Hidrocortisona/sangre , Inflamación/etiología , Inflamación/veterinaria , Cojera Animal/epidemiología , Cojera Animal/etiología , Recuento de Leucocitos/veterinaria , Locomoción , Leche/química , Proteínas de la Leche/análisis , Dolor/etiología , Dolor/veterinaria , Embarazo
13.
J Dairy Sci ; 96(11): 7223-7233, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24054297

RESUMEN

Objectives of this study were to determine the physiological effects of psychological stress applied to dairy calves and to test if molasses consumption could be used to validate that a stressed condition was achieved. Twenty male calves (3 wk old) received jugular catheters and were randomly assigned to control (CTR; n = 4 pens of 1 calf per pen) or social stress treatments (STR; n = 4 pens of 4 calves per pen). The STR treatment included 5 cycles of 24-h isolation followed by regrouping with unfamiliar animals for 48 h (over 15 d). An ACTH challenge (0.1 IU/kg of body weight) was used to determine adrenal fatigue. Peak and total cortisol concentrations were greater for STR calves until the ACTH challenge. After the ACTH challenge, CTR calf cortisol increased and STR calf cortisol continued to decrease, suggesting adrenal fatigue. The number of calves that became positive for fecal shedding of Salmonella after the acute stress of being moved and the number of calves that were positive after the move decreased with each move. Fifty-six percent of STR calves changed from negative to positive for shedding after the first move compared with 18.75% of STR calves remaining negative after the third move. Difference in fecal shedding of Enterobacteriaceae from samples taken before and after moving calves on d 6 was less than that on d 2, 3, and 5. Leukocyte counts were not different, but trends for day effects were detected for neutrophil and monocyte percentages. Molasses consumption was greater for STR calves on d 2 and 11, as was total consumption. Latency to lie after eating also increased as the study progressed; STR calves required more time to lie after eating on d 12 than on d 3, and latency to lie was greater for STR than CTR on d 4, 8, 12, and 14. The STR calves also stood more than the CTR calves in the 4-h afternoon period on d 4, 5, 7, and 14. However, during the 4-h morning observations on d 14 (ACTH challenge), CTR calves stood more than STR calves. This model induced chronic stress, as characterized by adrenal fatigue, which was confirmed by molasses consumption and behavior changes. Therefore, molasses consumption could be used to confirm social stress in experimental models.


Asunto(s)
Enfermedades de los Bovinos/fisiopatología , Aglomeración/psicología , Estrés Psicológico/fisiopatología , Hormona Adrenocorticotrópica/farmacología , Animales , Derrame de Bacterias , Peso Corporal/efectos de los fármacos , Bovinos , Enfermedades de los Bovinos/etiología , Ingestión de Alimentos/fisiología , Enterobacteriaceae , Heces/microbiología , Hidrocortisona/sangre , Recuento de Leucocitos/veterinaria , Masculino , Melaza , Estrés Psicológico/etiología
14.
Evol Comput ; 21(1): 29-64, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-22122384

RESUMEN

Evolution strategies (ESs) are powerful probabilistic search and optimization algorithms gleaned from biological evolution theory. They have been successfully applied to a wide range of real world applications. The modern ESs are mainly designed for solving continuous parameter optimization problems. Their ability to adapt the parameters of the multivariate normal distribution used for mutation during the optimization run makes them well suited for this domain. In this article we describe and study mixed integer evolution strategies (MIES), which are natural extensions of ES for mixed integer optimization problems. MIES can deal with parameter vectors consisting not only of continuous variables but also with nominal discrete and integer variables. Following the design principles of the canonical evolution strategies, they use specialized mutation operators tailored for the aforementioned mixed parameter classes. For each type of variable, the choice of mutation operators is governed by a natural metric for this variable type, maximal entropy, and symmetry considerations. All distributions used for mutation can be controlled in their shape by means of scaling parameters, allowing self-adaptation to be implemented. After introducing and motivating the conceptual design of the MIES, we study the optimality of the self-adaptation of step sizes and mutation rates on a generalized (weighted) sphere model. Moreover, we prove global convergence of the MIES on a very general class of problems. The remainder of the article is devoted to performance studies on artificial landscapes (barrier functions and mixed integer NK landscapes), and a case study in the optimization of medical image analysis systems. In addition, we show that with proper constraint handling techniques, MIES can also be applied to classical mixed integer nonlinear programming problems.


Asunto(s)
Algoritmos , Vasos Coronarios/diagnóstico por imagen , Ultrasonografía
15.
JDS Commun ; 4(6): 458-463, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38045903

RESUMEN

The objective of this study was to compare ß-casein genotype of purebred certified-organic Holstein cows, and their effect on production, fertility, and survival. Holstein cows (n = 1,982) from 13 certified-organic dairy herds from the western, midwestern, and northeastern United States were genomically tested with CLARIFIDE Plus (Zoetis) for ß-casein genotype. Two hundred fourteen cows were A1A1 (11%), 848 cows were A1A2 (43%), and 920 cows were A2A2 (46%). In total, 2,249 lactation records, 1,025 from the first parity and 1,224 records during second and greater parities were used. Test-day milk, fat, and protein production (305-d) and somatic cell score were obtained from the Dairy Herd Improvement Association. A lower limit of 50 d for days open was applied, and cows with more than 250 d open had days open set to 250 d. Independent variables for statistical analysis were the fixed effects of herd, parity, ß-casein genotype (A1A1, A1A2, A2A2), and ß-casein genotype by parity interaction. Cow nested within parity was the random effect in the statistical models for fertility and production traits. Herd had a significant effect on all fertility, production, and survival variables. Parity affected the number of times bred per pregnancy and days open, milk, fat, and protein production, and somatic cell score. Beta-casein genotype and herd influenced the percentage of cows surviving to first and second lactation. Results indicate no difference in production and fertility regarding ß-casein genotype for organic dairy herds. Survival was biased against the A1 allele, which is indicated by lower survival rates during first lactation. These results may offer organic producers more flexibility in breeding and culling decisions to produce A2A2 milk.

16.
Mol Microbiol ; 78(4): 932-46, 2010 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-20815824

RESUMEN

The Bam complex is a highly conserved multiprotein machine essential for the assembly of ß-barrel outer membrane proteins. It is composed of the essential outer membrane protein BamA and four outer membrane associated lipoproteins BamB-E. The Yersinia enterocolitica Adhesin A (YadA) is the prototype of trimeric auotransporter adhesins (TAAs), consisting of a head, stalk and a ß-barrel membrane anchor. To investigate the role of BamA in biogenesis of TAAs, we expressed YadA in a BamA-depleted strain of Escherichia coli, which resulted in degradation of YadA. Yeast-two-hybrid experiments and immunofluorescence studies revealed that BamA and YadA interact directly and colocalize. As BamA recognizes the C-terminus of OMPs, we exchanged the nine most C-terminal amino acids of YadA. Substitution of the amino acids in position 1, 3 or 5 from the C-terminus with glycine resulted in DegP-dependent degradation of YadA. Despite degradation all YadA proteins assembled in the outer membrane. In summary we demonstrate that (i) BamA is essential for biogenesis of the TAA YadA, (ii) BamA interacts directly with YadA, (iii) the C-terminal amino acid motif of YadA is important for the BamA-dependent assembly and differs slightly compared with other OMPs, and (iv) BamA and YadA colocalize.


Asunto(s)
Adhesinas Bacterianas/metabolismo , Aminoácidos/metabolismo , Proteínas de la Membrana Bacteriana Externa/metabolismo , Proteínas de Escherichia coli/metabolismo , Multimerización de Proteína , Yersinia enterocolitica/metabolismo , Adhesinas Bacterianas/genética , Sustitución de Aminoácidos/genética , Aminoácidos/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Mutagénesis Sitio-Dirigida , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Técnicas del Sistema de Dos Híbridos
17.
Nat Med ; 6(5): 583-8, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10802717

RESUMEN

The pro-inflammatory cytokine interleukin (IL)-6 (refs. 1-5) can bind to cells lacking the IL-6 receptor (IL-6R) when it forms a complex with the soluble IL-6R (sIL-6R) (trans signaling). Here, we have assessed the contribution of this system to the increased resistance of mucosal T cells against apoptosis in Crohn disease (CD), a chronic inflammatory disease of the gastrointestinal tract. A neutralizing antibody against IL-6R suppressed established experimental colitis in various animal models of CD mediated by type 1 T-helper cells, by inducing apoptosis of lamina propria T cells. Similarly, specific neutralization of sIL-6R in vivo by a newly designed gp130-Fc fusion protein caused suppression of colitis activity and induction of apoptosis, indicating that sIL-6R prevents mucosal T-cell apoptosis. In patients with CD, mucosal T cells showed strong evidence for IL-6 trans signaling, with activation of signal transducer and activator of transcription 3, bcl-2 and bcl-xl. Blockade of IL-6 trans signaling caused T-cell apoptosis, indicating that the IL-6-sIL-6R system mediates the resistance of T cells to apoptosis in CD. These data indicate that a pathway of T-cell activation driven by IL-6-sIL-6R contributes to the perpetuation of chronic intestinal inflammation. Specific targeting of this pathway may be a promising new approach for the treatment of CD.


Asunto(s)
Apoptosis/inmunología , Colitis Ulcerosa/inmunología , Enfermedad de Crohn/inmunología , Interleucina-6/metabolismo , Linfocitos T/inmunología , Adulto , Animales , Antígenos CD/metabolismo , Receptor gp130 de Citocinas , Proteínas de Unión al ADN/metabolismo , Femenino , Humanos , Masculino , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos BALB C , Persona de Mediana Edad , Modelos Inmunológicos , Unión Proteica , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Receptores de Interleucina-6/antagonistas & inhibidores , Factor de Transcripción STAT3 , Transducción de Señal , Transactivadores/metabolismo , Proteína bcl-X
18.
Phys Chem Chem Phys ; 13(32): 14750-7, 2011 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-21748190

RESUMEN

An efficient model describing the He-atom scattering process is presented. The He-surface interaction potential is calculated from first principles by exploiting second-order Rayleigh-Schrödinger many-body perturbation theory and fitted by using a variety of pairwise interaction potentials. The attractive part of the fitted analytical form has been upscaled to compensate the underestimation of the well depth for this system in the perturbation theory description. The improved potential has been introduced in the close-coupling method to calculate the diffraction pattern. Quantitative agreement between the computed and observed binding energy and diffraction intensities for the He-MgO(100) system is achieved. It is expected that the utility of He scattering for probing dynamical processes at surfaces will be significantly enhanced by this quantitative description.

19.
J Chem Phys ; 134(1): 014706, 2011 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-21219019

RESUMEN

He-atom scattering is a well established and valuable tool for investigating surface structure. The correct interpretation of the experimental data requires an accurate description of the He-surface interaction potential. A quantum-mechanical treatment of the interaction potential is presented using the current dominant methodologies for computing ground state energies (Hartree-Fock, local and hybrid-exchange density functional theory) and also a novel post-Hartree-Fock ab initio technique for periodic systems (a local implementation of Mo̸ller-Plesset perturbation theory at second order). The predicted adsorption well depth and long range behavior of the interaction are compared with that deduced from experimental data in order to assess the accuracy of the interaction potential.


Asunto(s)
Helio/química , Óxido de Magnesio/química , Teoría Cuántica , Propiedades de Superficie
20.
Infect Immun ; 78(6): 2677-90, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20308293

RESUMEN

Yersinia adhesin A (YadA) is a trimeric autotransporter adhesin with multiple functions in host-pathogen interactions. The aim of this study was to dissect the virulence functions promoted by YadA in vitro and in vivo. To accomplish this, we generated Yersinia enterocolitica O:8 mutants expressing point mutations in YadA G389, a highly conserved residue in the membrane anchor of YadA, and analyzed their impact on YadA expression and virulence functions. We found that point mutations of YadA G389 led to impaired transport, stability, and surface display of YadA. YadA G389A and G389S mutants showed comparable YadA surface expression, autoagglutination, and adhesion to those of wild-type YadA but displayed reduced trimer stability and complement resistance in vitro and were 10- to 1,000-fold attenuated in experimental Y. enterocolitica infection in mice. The G389T, G389N, and G389H mutants lost trimer stability, exhibited strongly reduced surface display, autoagglutination, adhesion properties, and complement resistance, and were avirulent (>10,000-fold attenuation) in mice. Our data demonstrate that G389 is a critical residue of YadA, required for optimal trimer stability, transport, surface display, and serum resistance. We also show that stable trimeric YadA protein is essential for virulence of Y. enterocolitica.


Asunto(s)
Adhesinas Bacterianas/química , Multimerización de Proteína , Factores de Virulencia/química , Yersinia enterocolitica/química , Yersinia enterocolitica/patogenicidad , Adhesinas Bacterianas/genética , Adhesinas Bacterianas/metabolismo , Animales , Adhesión Bacteriana , Actividad Bactericida de la Sangre , Recuento de Colonia Microbiana , Proteínas del Sistema Complemento/inmunología , Femenino , Células HeLa , Humanos , Ganglios Linfáticos/microbiología , Proteínas de la Membrana/análisis , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Mutagénesis Sitio-Dirigida , Mutación Missense , Ganglios Linfáticos Agregados/microbiología , Mutación Puntual , Estabilidad Proteica , Bazo/microbiología , Bazo/patología , Análisis de Supervivencia , Virulencia , Factores de Virulencia/genética , Factores de Virulencia/metabolismo , Yersiniosis/mortalidad , Yersiniosis/patología , Yersinia enterocolitica/genética
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